Retracting mechanism for ball point pens and the like



B. D. SMITH June 19, 1956 RETRACTING MECHANISM FOR BALI.. POINT PENS AND THE LI`KE Filed Aug. 14. 1953 INVENTOR.

...... i Ww l 0 3 4 4 f f a 2 e a 3 4 M Z Z u 4M 1 By sLA/vc/:Ro o. sM/rH RETRACTING MECHANSM FOR BALL POIN PENS AND THE LIKE l Blanchard D. Smith, Atlanta, Ga., assigner to Scripta,

Inc., Atlanta, Ga., a corporation of Georgia Application August 14, 1953, Serial No. 374,395 Y 3 Claims. (Cl. 120-42.03)

This invention relates to means for selectively controlling movement of ball point pen units or similar elements between projected and retracted positions with respect to a barrel or housing therefor.

The means provided according to the present invention for this purpose is characterized by a retracting mechanism that is arranged as a complete self contained unit, that is operated from a single plunger element through selective sliding and rotating movement ofthe plunger, and that is provided with a latching device in` which no overtravel whatever is necessary in latching or releasing the mechanism.

These and other features of the present invention are described in further detail below in connection with the portion of the plunger guide bracket according to the i present invention.

Fig. 4 is a plan view of the blank from which the gui-de bracket of the retracting mechanism is formed;

Fig. 5 is a vetrical section (taken at the position 5-5 in Fig. 3) of the guide bracket as formed for use;

Fig. 6 is a top view (corresponding to Fig. 3) of the guide bracket as formed for use;

Fig. 7 is an elevation, partly in section, of the plunger member for the retracting mechanism;

Fig. 8 is a bottom plan view corresponding to Fig. 7;

Fig. 9 is an elevation, partly in section, of the rear housing portion of the pen barrel; and

Fig. l0 is a fragmentary elevation of the rear assembly end of the front barrel portion.

The present invention is illustrated in the drawings as incorporated in a ball point writing instrument having a ball point and reservoir unit 10 retractably arranged within a pen barrel formed by a forward barrel portion 12 and a rear barrel portion or housing member 14.

Because the retracting mechanism of the present invention requires no overtravel in latching, as previously mentioned, the ball point unit 10 may consist of a ball point element 16 fitted within the forward end of a flexible plastic (e. g., polyethylene) ink reservoir 18, and the forward barrel portion 12 may be formed to support the ink reservoir 1S laterally, as by longitudinal ribs 20, for bottoming of the ball point element 16 at a writing tip shoulder 22 therein, so that the ball point unit will be held firmly in projected position for writing, as disclosed more fully and claimed in copending applications Serial No. 357,184, tiled May 25, 1953, now abandoned, and Serial No. 386,946, led October 19, 1953.

nited States Patent ICC The rear barrel portion 14 forms a tubular housing in which the retracting mechanism of the present invention is contained, and is suitably assembled on a reduced rear end length of the forward barrel portion 12 by means of an inwardly extruded boss 24 arranged adjacent its forward end to iit a bayonet slot 26 provided at the rear of the forward barrel portion 12 (see Fig. l0). The rear end of the tubular housing formed by the rear barrel portion 14 terminates at an inwardly ex- .tending annular ange 28 through the opening of which a plunger 30 projects rearwardly.

The plunger tl extends forwardly within the tubular housing 14 to receive and grip the rear end of the ink reservoir, and for this purpose the forwardly extending end of plunger 36 is formed with a longitudinally slotted tubular portion 32 surrounding in spaced relation an inner plug portion 34 adapting it as a clutch. The plug portion 34 has a at sidedshape in cross section and is partially shouldered` adjacent its base (as at 36) so as to provide for venting the ink reservoir.

The plunger 3() is carried within the tubular housing 14 by a guide bracket that is indicated generally by the reference numeral 38. This guide bracket 38 is fixed in the tubular housing-14 beneath the annular flange 28, and is formed with opposed ilange portions 40 and 42 disposed transversely in spaced relation within the tubular housing 14 and with an interconnecting shank portion 44 at one side thereof. The opposed ange portions 40 and 42 are formed with aligned apertures 46 and 43 .in which the plunger 30 is disposed for sliding movement as well as for rotation The plunger 30 is fitted with a lateral projection, suitably formed by a pin 50 fixed transversely therein, that extends between the bracket flange portions 40 and 42 for abutment at a side edge of the bracket shank portion 44. Surrounding the plunger 30, between the bracket ilange portions 40 and 42, a coil spring 52 is arranged for bottoming in compression on the lower bracket flange 42, and for stressing in torsion between an anchorage for one end, as at 54, on the bracket 38 adjacent the lower flange 42 and an anchorage for the other end, as at 56, through engagement with the plunger pin 50, as illustrated diagrammatically in Fig. 3. By this arrange ment the plunger 3l) is yieldably biased for sliding movement rearwardly in the direction of its projection from the tubular housing 14, as well as rotatably in one direction so that the plunger pin S0 is yieldably maintained in abutting relation with the opposing side edge of the bracket shank portion 44. Intermediate its length, this opposing side edge of the bracket shank 44 is formed with a forwardly facing latching notch 58 for engaging the plunger pin S0.

Accordingly, upon depression of the plunger 30 forwardly within the tubular housing 14, against the slidable bias thereon, latching of the plunger pin 50 at the latching notch 58 results, by reason of the rotatable bias on the plunger 30, in the holding of the ball point unit 10 in projected position for writing; while the forwardly latched plunger 3l) is relcasable for return with the ball point unit 10 to its normal rearwardly projecting or retracted position, under the force of the slidable bias thereon, simply by rotation against the rotatable bias imposed thereon by the torsion stress of the coil spring 52. Preferably, the holding edge of the latching notch 58 is inclined outwardly towards the rear of the tubular housing 14 to render engagement and release of the plunger pin 50 smoother and easier.

The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise except as dened in the appended claims.

i claim:

1. A retracting mechanism for a ball point pen or the like, said mechanism comprising a guide bracket having opposed ange portions joined in spaced relation by a shank portion at one side thereof, said opposed 'flange portions being formed with aligned apertures, a plunger slidably and rotatably extending through said apertures, a pin xed transversely in said plunger between said opposed flange portions, said pin extending laterally from said plunger for abutment at a side edge of said shank portion, and a torsion spring anchored at one end on said bracket adjacent one flange portion thereof and engaging said pin at the other end for yieldably maintain-` .ing the extending portion thereof in abutting relation with said shank side edge, said spring also acting in compression to bias said pin yieldably toward said other ange portion, and said shank side edge being formed with a notch intermediate .its length having an edge facing away from said other flange portion, whereby said plunger may be latched at a shifted position with respect to said guide bracket upon movement disposing said pin at said notch and may be unlatched by rotation against the pull of said torsion spring.

2. A retracting mechanism for a ball point pen or the like, said mechanism comprising a tubular housing rnernber, a guide bracket xed in said housing member and having'opposed ange portions spaced transversely therein with an interconnecting shank portion at one side thereof, said flange portions being formed with aligned apertures, a plunger slidably and rotatably extending through said apertures and projecting from one end of said housing member, a lateral projection on said plunger extending between said flange portions for abutment at a side edge ot said shank portion, and a coil spring surrounding said plunger between said flange portions, said spring being bottomed in compression on the flange portion remote from the projecting end of said plunger and stressed in torsion between one end anchored on said bracket adjacent said remote flange portion and the other end engaging said lateral plunger projection, said torsion stress yieldably maintaining said projection in abutting relation with said shank side edge, and said shank side edge being formed intermediate ,its length with a notch having an edge facing toward said remote ange portion, whereby said plunger may be latched at a depressed position within said housing member by movement thereof disposing said lateral projection at said notch and may be -unlatched by rotation against the torsion stress of said spring.

3. A retracting mechanism for a ball point pen or the like, said mechanism comprising a guide bracket having opposed Piange portions joined in spaced relation by a shank portion at one side thereof, said opposed ilangc portions being formed with aligned apertures, a plunger slidably and rotatably extending through said apertures, a lateral projection on said plunger extending for abutment at a side edge of said shank portion, and a torsion spring anchored at one end on said bracket adjacent one flange portion thereof and engaging said lateral projection at the other end for yieldably maintaining said projection in abutting relation with said shank side edge, said spring also acting in compression to bias said projection yieldably toward said other ange portion, and said shank side edge being formed with a notch intermediate its-length having an edge facing away from said other ange portion, whereby said plunger may bc latched at a shifted position with respect to said guide bracket upon movement disposing said projection at said notch and may be unlatched by rotation against the pull of said vtorsion spring.

References Cited in the file of this patent UNITED STATES PATENTS Weisser et al Jan. 6, 1953 

